Holiday shopping is expected to boost annual e-commerce sales by 16% to more than $525.7 billion in 2018, according to research firm eMarketer. The sharp rise in e-commerce sales has put pressure on retailers to implement omnichannel strategies for on-line order fulfillment. Part of this implementation has shifted goods from retail shelves to warehouse racks, increasing industrial warehouse demand. For every $1 billion increase in e-commerce sales, an estimated 1.25 million sq. ft. of warehouse space is needed to keep up with demand. Thus, e-commerce generated warehouse demand could grow by an additional 191.2 million sq. ft. from 2018 to 2020.